Training Performed Above Lactate Threshold Decreases p53 and Shelterin Expression in Mice

Abstract

Telomere shortening is associated to sarcopenia leading to functional impairment during aging. There are mechanisms associated with telomere attrition, as well to its protection and repair. Physical training is a factor that attenuates telomere shortening, but little is known about the effects of different exercise intensities on telomere biology. Thus, we evaluated the effects of exercise intensity (moderate vs. high-intensity domain) on gene expression of senescence markers Checkpoint kinase 2 and tumor suppressor ( and , respectively), shelterin telomere repeat binding 1 and 2 (/), DNA repair (), telomerase reverse transcriptase () and telomere length in middle aged mice. Three groups were studied: a control group (CTL) and two groups submitted to swimming at intensities below the lactate threshold (LI group) and above the lactate threshold (HI group) for 40 and 20 min respectively, for 12 weeks. After training, the HI group showed reduction in p53 expression in the muscle, and decreased shelterin complex expression when compared to LI group. No differences were observed between groups for expression and telomere length. Thus, exercise training in high-intensity domain was more effective on reducing markers of senescence and apoptosis. The higher intensity exercise training also diminished shelterin expression, with no differences in telomere length and mTERT expression. Such results possibly indicate a more effective DNA protection for the higher-intensity exercise training.

Faster and Healthier: Relationship between Telomere and Performance in Master Athletes

“…Cell death is responsible for tissue function loss, which could impair general health and performance, especially if the tissue is skeletal muscle. On the other hand, Cunha, Dos Santos Rosa, Sales, et al [36] compared the effects of moderate vs. high-intensity exercise training on markers of senescence. The authors concluded that high-intensity training, such as that usually performed lifelong by MAs, was associated with decreased markers of senescence and apoptosis, including a reduction in p53 expression in the skeletal muscle, indicating more effective DNA protection.…”

Biomarkers and Redox Balance in Aging Rats after Dynamic and Isometric Resistance Training

“…Conversely, interventions of aerobic training have shown to reduce the mRNA of p53, Trf1 and Trf2, and Xrcc5 in the skeletal muscle of elderly mice. This evidence indicates that aerobic training reduced DNA damage in muscle cells caused by aging [23].…”

“…Relative quantification (RQ) between samples was calculated according to delta method delta Cq (2 − ΔΔCq ). Relative telomere measurement was performed using the SYBR Green System (Applied Biosystems), and analyses were performed using the relative standard curve method as described de Carvalho Cunha et al [23].…”

“…Telomere relative length and gene expressions were analyzed following procedures outlined by de Carvalho Cunha et al [23]. Genomic DNA was extracted using QIamp genomic DNA Kit (QIAgen).…”

“…A total of 20 ng genomic DNA was added to a reaction mixture containing 1X SYBR Green Master mix (Applied Biosystems), 220 nM forward and reverse primers for the T (telomere) PCR, and 301 nM forward and 502 nM reverse for the S (single-copy gene) PCR. Cycling conditions for the PCR followed those described by de Carvalho Cunha et al [23]. Telomere relative length was measured from genomic DNA (telomere PCR/single copy gene PCR, T/S) using the qPCR method as previously described by de Carvalho Cunha et al [23].…”